In development work, it’s not enough to simply run programmes or launch projects—understanding whether they actually work and how well they work matters deeply. Impact evaluation helps answer this essential question: Did our efforts make a real difference? By grounding decisions in evidence rather than assumptions, impact evaluation becomes a foundation for smarter, more effective development.

Why Impact Evaluation Matters #

At its core, impact evaluation reveals whether an intervention caused the outcomes it set out to achieve. This isn’t just about counting outputs or milestones; it’s about understanding changes in people’s lives that can be linked back to the programme itself. This focus on cause and effect supports evidence-based decision making in projects, ensuring that development strategies are shaped by reliable information, not guesswork.

Benefits of Impact Evaluation for NGOs and Development Actors #

• Impact evaluations offer many advantages, especially for NGOs and practitioners striving for real-world change:
• Improving Program Effectiveness Through Evaluation: By uncovering what works and what doesn’t, organisations can refine and improve programme design and delivery.
• Demonstrating Social Impact Through Evaluation: Evaluations help NGOs show donors, communities, and partners the actual difference their work makes, boosting credibility and support.
• Accountability and Learning in Development: Transparent evaluation results foster trust and accountability to stakeholders while also serving as a powerful learning tool for future initiatives.
• Evidence-Based Decision Making in Projects: With concrete findings, teams can allocate scarce resources more effectively, expanding successful programmes and adjusting or ending those that fall short.

A Tool for Change and Continuous Improvement #

Impact evaluation isn’t just about past performance; it’s a catalyst for ongoing learning, innovation, and deeper understanding. By weaving rigorous evidence into planning and implementation, organisations boost their chance of delivering real, measurable development gains that enrich lives and strengthen communities.

List of recommended resources #

For a broad overview #

Applicability of impact evaluation methodologies in development and social action initiatives

In this study, Elena Ripoll examines and organizes a range of impact evaluation methods to support their appropriate selection and use, particularly in organizations where such approaches are not yet widely adopted. The study also highlights the value of impact evaluations in enhancing resource use and strengthening the results of development and social intervention programmes.

Impact Evaluations and Development: NoNIE Guidance on Impact Evaluation

This report by Leeuw Frans and Vaessen Jos provides a broad overview of how to evaluate the impact of a development project or program. The report identifies that the impacts produced by an intervention requires an attempt to gauge what would have occurred in its absence.

For in-depth understanding #

Impact Evaluation in International Development: Theory, Methods and Practice

This book by Paul Glewwe and Petra Todd provides a comprehensive exposition of how to conduct different types of impact evaluations such as using statistical and econometric methods, randomized controlled trials, regression discontinuity methods etc. 

Impact Evaluation of Development Interventions: A Practical Guide

In this book, Howard White and David A. Raitzer present a practical overview of the principles, approaches, and real-world application of impact evaluation. It explains key concepts and methods involved in planning, designing, managing, and carrying out impact evaluations, supported by illustrative examples.

Case study  #

Evaluating the Impact of Egyptian Social Fund for Development Programs

This paper investigates the size of the impact of the Egyptian Social Fund for Development’s interventions, whether the benefits have been commensurate with the costs, and whether the programs have been targeted successfully to the poor. The impact evaluation used here applies propensity-score matching to data from the 2004/2005 national Household Income, Expenditure and Consumption Survey. 

Impact Evaluation Helps Deliver Development Projects

This paper by Arianna Legovini, Vincenzo Di Maro, and Ciao Piza analyzes the question – Does impact evaluation research help or hinder the delivery of development projects? – by constructing a new data set of 100 impact evaluations and 1,135 projects approved by the World Bank between 2005 and 2011. 

References #

The growth of impact evaluation for international development: how much have we learned?

Understanding Impact Evaluation: Definition, Benefits, and Best Practices